Existence and void : happy couple

Do we exist ? Or just because we think we exist that we actually live in existence ? Or maybe , because each would prove that a creature before his eyes is touchable and it's moving so it exists , therefore he exists . But , when you're alone and no one is there to observe , Can you feel your existence ? Actually atoms are made of 99% void , so practically we're not here, we're just dust . But dust is something . It can be moved .But When something can't move on its own, Does it exist?